EFFECT OF WIND LOADS ON NON REGULARLY SHAPED HIGH-RISE BUILDINGS

Wind loads have historically been recognized as one of the most important issue in high-rise buildings analysis and design. In particular, in regions of low seismic intensity, a high-rise building lateral design is controlled by wind loads. In wind analysis, Computational Fluid Dynamics (CFD) and/or wind tunnel testing are required to calculate the external pressures acting on a building. In this paper, two case studies are presented to show how the wind loads are calculated and applied in design. The first case study is based on the CFD results for the New Marina Casablanca Tower in Casablanca, Morocco. The second case study considers the results from the wind tunnel test studies conducted for the Al- Hamra tower, in Kuwait City, Kuwait. The New Marina Casablanca tower is a 167m tall concrete building, with a unique twisting shape generated from the relative rotation of two adjacent floors. Sloped columns are introduced in the perimeter to follow the tower outer geometry and to support the concrete slabs spanning between the central core and the perimeter frame. The effects of wind loads on the twisted geometry has been studied in details since the pressure coefficients are not easily identified for such a complex form. In addition, the effect of the wind loads on the structure presented unique challenges that required innovative structural solutions. The Al-Hamra tower is a 412m tall concrete building with a sculpted twisting form which optimizes the views to the Arabian Gulf while minimizing the solar heat gain. The complex form is realized using sloped walls and vertical columns on the perimeter and a central concrete core. The unique shape of the tower presented several design challenges related to the wind loads on the structure. This paper will discuss the unique challenges and solutions associated with wind loads effect on buildings of unique form

INTEGRANDO SUSTENTABILIDADE AMBIENTAL AO PORTFÓLIO DE PROJETOS: ESTUDO DE CASO NO SETOR DE CONSTRUÇÃO

A relação entre a sustentabilidade ambiental e o gerenciamento de projetos apresenta-se cercada de desafios. A agilidade na gestão de projetos não parece ser compatível com a perspectiva de sustentabilidade a longo prazo. No entanto, o gerenciamento de projetos sustentáveis tem sido apontado como uma das mais importantes tendências globais, pois o número de publicações acadêmicas sobre o tema está em constante crescimento. Nesse contexto, o objetivo deste artigo foi de compreender como a gestão de portfólio de projetos integra práticas de gestão ambiental e realiza a tomada de decisão sobre os projetos em uma grande empresa do setor de construção civil. Para alcançar os objetivos desta pesquisa, um estudo de caso foi conduzido. Dentre os principais resultados, notou-se que o envolvimento de uma equipe multidisciplinar, com a presença de um especialista em gestão ambiental é fator positivo à boa gestão de portfólio, pois o conhecimento técnico permite melhor avaliação de benefícios e riscos. Percebeu-se que, mesmo que a empresa gerencie a questão ambiental de forma eficiente e prioritária, durante as etapas da gestão de portfólio, avaliações financeiras ainda têm maior peso no apoio à tomada de decisão, pois estão diretamente ligadas à viabilidade dos projetos, entretanto, para situações nas quais os riscos e impactos ambientais são altos, os indicadores financeiros passam a não ser priorizados

Progression of human carotid and femoral atherosclerosis: a prospective follow-up study by magnetic resonance vessel wall imaging

Aims The time course of atherosclerosis burden in distinct vascular territories remains poorly understood. We longitudinally evaluated the natural history of atherosclerotic progression in two different arterial territories using high spatial resolution magnetic resonance imaging (HR-MRI), a powerful, safe, and non-invasive tool. Methods and results We prospectively studied a cohort of 30 patients (mean age 68.3, n = 9 females) with high Framingham general cardiovascular disease 10-year risk score (29.5%) and standard medical therapy with mild-to-moderate atherosclerosis intra-individually at the level of both carotid and femoral arteries. A total of 178 HR-MRI studies of carotid and femoral arteries performed at baseline and at 1- and 2-year follow-up were evaluated in consensus reading by two experienced readers for lumen area (LA), total vessel area (TVA), vessel wall area (VWA = TVA − LA), and normalized wall area index (NWI = VWA/TVA). At the carotid level, LA decreased (−3.19%/year, P = 0.018), VWA increased (+3.83%/year, P = 0.019), and TVA remained unchanged. At the femoral level, LA remained unchanged, VWA and TVA increased (+5.23%/year and +3.11%/year, both P < 0.01), and NWI increased for both carotid and femoral arteries (+2.28%/year, P = 0.01, and +1.8%/year, P = 0.033). Conclusion The atherosclerotic burden increased significantly in both carotid and femoral arteries. However, carotid plaque progression was associated with negative remodelling, whereas the increase in femoral plaque burden was compensated by positive remodelling. This finding could be related to anatomic and flow differences and/or to the distinct degree of obstruction in the two arterial territorie

INTEGRANDO SUSTENTABILIDADE AMBIENTAL AO PORTFÓLIO DE PROJETOS: ESTUDO DE CASO NO SETOR DE CONSTRUÇÃO

A relação entre a sustentabilidade ambiental e o gerenciamento de projetos apresenta-se cercada de desafios. A agilidade na gestão de projetos não parece ser compatível com a perspectiva de sustentabilidade a longo prazo. No entanto, o gerenciamento de projetos sustentáveis tem sido apontado como uma das mais importantes tendências globais, pois o número de publicações acadêmicas sobre o tema está em constante crescimento. Nesse contexto, o objetivo deste artigo foi de compreender como a gestão de portfólio de projetos integra práticas de gestão ambiental e realiza a tomada de decisão sobre os projetos em uma grande empresa do setor de construção civil. Para alcançar os objetivos desta pesquisa, um estudo de caso foi conduzido. Dentre os principais resultados, notou-se que o envolvimento de uma equipe multidisciplinar, com a presença de um especialista em gestão ambiental é fator positivo à boa gestão de portfólio, pois o conhecimento técnico permite melhor avaliação de benefícios e riscos. Percebeu-se que, mesmo que a empresa gerencie a questão ambiental de forma eficiente e prioritária, durante as etapas da gestão de portfólio, avaliações financeiras ainda têm maior peso no apoio à tomada de decisão, pois estão diretamente ligadas à viabilidade dos projetos, entretanto, para situações nas quais os riscos e impactos ambientais são altos, os indicadores financeiros passam a não ser priorizados

Modelling the PbLi flow including tritium transport and permeation with GETTHEM

One of the main challenges to be addressed to achieve a reliable electricity production from the EU DEMO reactor is the realization of a closed fuel cycle, for which a suitable Tritium Extraction and Removal System (TERS) is required. One of the possible technologies identified for the EU DEMO TERS is the Permeator Against Vacuum (PAV): the tritium dissolved in the liquid PbLi flowing within several parallel channels will permeate towards the vacuum pumped on the other side of the channel wall (the membrane).A recently-developed model of the tritium permeation across the membrane in the PAV, involving both transport phenomena in the wall and surface processes, was already used to size the EU DEMO PAV. However, besides the component itself, it is important to properly define the interfaces of the PAV in the TERS, and of the TERS in the entire PbLi and tritium loops. The model of such a complex system is therefore implemented here in the Modelica object-oriented language used by system-level tool GETTHEM, that already includes a model of the PbLi loop. The resulting, lumped-parameter component will be able to capture the thermal-hydraulic behaviour of the PbLi, to model the tritium transport in the fluid and to estimate the tritium permeated flux supplied to the tritium processing. Such a model is tested here on a sub-scale circuit to demonstrate its capability to simulate the operation of the EU DEMO TERS using the GETTHEM code.As the physical parameters of the model are subject to a large uncertainty, an uncertainty propagation analysis is also performed, to have a preliminary quantification of the impact of such uncertainties on the model output and, therefore, on the TERS efficiency, and to drive further investigations of these physical properties. In particular, results show how the uncertainty on the solubility constant of hydrogen in PbLi represents the dominant contribution on the total variance, highlighting the need for a better accuracy of such parameter

Noninvasive respiratory support in the hypoxaemic peri-operative/periprocedural patient: a joint ESA/ESICM guideline

Hypoxaemia is a potential life-threatening yet common complication in the peri-operative and periprocedural patient (e.g. during an invasive procedure at risk of deterioration of gas exchange, such as bronchoscopy). The European Society of Anaesthesiology (ESA) and the European Society of Intensive Care Medicine (ESICM) developed guidelines for the use of noninvasive respiratory support techniques in the hypoxaemic patient in the peri-operative and periprocedural period. The panel outlined five clinical questions regarding treatment with noninvasive respiratory support techniques [conventional oxygen therapy (COT), high flow nasal cannula, noninvasive positive pressure ventilation (NIPPV) and continuous positive airway pressure (CPAP)] for hypoxaemic patients with acute peri-operative/periprocedural respiratory failure. The goal was to assess the available literature on the various noninvasive respiratory support techniques, specifically studies that included adult participants with hypoxaemia in the peri-operative/periprocedural period. The literature search strategy was developed by a Cochrane Anaesthesia and Intensive Care trial search specialist in close collaboration with the panel members and the ESA group methodologist. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to assess the level of evidence and to grade recommendations. The final process was then validated by both ESA and ESICM scientific committees. Among 19 recommendations, the two grade 1B recommendations state that: in the peri-operative/periprocedural hypoxaemic patient, the use of either NIPPV or CPAP (based on local expertise) is preferred to COT for improvement of oxygenation; and that the panel suggests using NIPPV or CPAP immediately post-extubation for hypoxaemic patients at risk of developing acute respiratory failure after abdominal surgery

Primary histiocytic sarcoma presenting as diffuse leptomeningeal disease: case description and review of the literature

Histiocytic sarcoma is a rare malignant neoplasm arising most commonly in lymph nodes, intestinal tract, skin and soft tissue. The incidence of primary CNS histiocytic sarcoma is even rarer with a total of just 27 cases reported in the literature so far. Herein we describe the first autopsy case of histiocytic sarcoma presenting as a diffuse leptomeningeal disease in absence of a CNS tumor-forming parenchymal lesion. The clinical, pathological and immunophenotypic features are described and an updated literature review on primary CNS histiocytic sarcoma is included